Examples of conventional emergency call boxes are disclosed in U.S. Pat. Nos. 5,377,256 and Re. 34,496. The disclosed call boxes include a cellular transceiver for bidirectional radiotelephonic communication of voice and data signals, and a controller for controlling the entire operation of the call box. The cellular transceiver and controller are contained within a rugged, tamper-resistant housing that is mounted on a roadside standard. The housing includes a door that opens to allow access to a standard telephone handset. The call box also includes various sensors that monitor the status of the call box to detect any abnormal conditions (for example, vandalism or door left open). Typically, the call box is powered by a battery whose charge is maintained by a solar panel mounted near the top of the standard.
When roadside assistance is required, a user opens the call box door and lifts the handset. This action causes a conventional handset hook switch to be activated to power up the call box. In response to a transition to an off hook switch condition, the microcontroller causes the cellular transceiver to dial a preprogrammed number for a central dispatch (or communication) center. Typically, the preprogrammed number is that of a highway patrol emergency dispatch center. Once the call is connected, an operator at the emergency dispatch center can communicate orally with the user and transmit and receive data, usually in the form of DTMF signals, to and from the call box. In this manner, the operator can control the operation of the call box and can request information from the call box such as the call box's identification number to provide the location of the user for dispatching roadside service.
Conventional call boxes can also initiate status calls to the emergency dispatch center or another preprogrammed number. For example, U.S. Pat. No. 5,016,269 discloses a call box whose controller places a daily report call to a central maintenance station (using a preprogrammed phone number) to report its present status and various statistics relating to its use. Additionally, the call box initiates an alarm call to the maintenance station or another preprogrammed number whenever certain status sensors detect an abnormal condition. Such conventional call boxes can also be remotely programmed from the central maintenance station. First, maintenance station personnel enter information that is to be used in programming a specific call box (or call boxes) in the maintenance station computer. Then, for example, when that call box places its next report call to the maintenance station, the maintenance station computer will program the call box with the new information. In this manner, call box parameters such as the emergency dispatch center telephone number and the time between report calls can be changed from the central maintenance station without the need to visit physically each of the roadside call boxes, which are dispersed over a wide geographic area.
While in such conventional call boxes, the preprogrammed number for the emergency dispatch center can be remotely changed, there exists a drawback in that all user-initiated calls are placed to the same preprogrammed phone number (i.e., the emergency dispatch center). However, many call box users that require assistance are not involved in true emergency situations. For example, a driver may use the call box to request assistance with a vehicle that is disabled on the roadside due to a lack of fuel or a flat tire. With a conventional call box, such non-emergency calls are included in the call traffic to the emergency dispatch center. Thus, the emergency dispatch operator must either handle non-emergency calls or determine that the call is not an emergency and transfer it to another number. This lessens the availability of the emergency operator to respond quickly to the true emergency situations.
Additionally, call box users who do not speak English cause a problem. The operator receiving the call must determine the language spoken by the user and route the call to an operator who speaks that language. This lessens the ability of the operator to respond quickly in an emergency situation. It may also be difficult for the user to determine the language being spoken by the user. Consequently, a call may have to be routed through several operators before an operator who can communicate with the user can be identified. This also results in the loss of valuable time. Furthermore, in conventional call boxes, the user and the operator can only communicate with one another using voice communication. Thus, a user who is deaf, hearing-impaired, or speech impaired may not be able to communicate the situation and the type of assistance required to the emergency operator. The difficulties experienced by a hearing-impaired user can also be aggravated by the fact that many emergency call boxes are located in extremely noisy roadside environments.